Mojo C++ bindings: remove the single-threaded Router.

mojo/public/cpp/bindings/lib/binding_state.h

Index: mojo/public/cpp/bindings/lib/binding_state.h
diff --git a/mojo/public/cpp/bindings/lib/binding_state.h b/mojo/public/cpp/bindings/lib/binding_state.h
index a947cf73c57c9d13b7a80370b33983e8c197863c..a57d904041dada28943cedc780cff9d6cde5b9b1 100644
--- a/mojo/public/cpp/bindings/lib/binding_state.h
+++ b/mojo/public/cpp/bindings/lib/binding_state.h
@@ -26,7 +26,6 @@
 #include "mojo/public/cpp/bindings/interface_ptr_info.h"
 #include "mojo/public/cpp/bindings/interface_request.h"
 #include "mojo/public/cpp/bindings/lib/multiplex_router.h"
-#include "mojo/public/cpp/bindings/lib/router.h"
 #include "mojo/public/cpp/bindings/message_header_validator.h"
 #include "mojo/public/cpp/bindings/scoped_interface_endpoint_handle.h"
 #include "mojo/public/cpp/system/core.h"
@@ -34,113 +33,10 @@
 namespace mojo {
 namespace internal {
 
-// Base class used for templated binding primitives which bind a pipe
-// exclusively to a single interface.
-class MOJO_CPP_BINDINGS_EXPORT SimpleBindingState {
+class MOJO_CPP_BINDINGS_EXPORT BindingStateBase {
  public:
-  SimpleBindingState();
-  ~SimpleBindingState();
-
-  void AddFilter(std::unique_ptr<MessageReceiver> filter);
-
-  bool HasAssociatedInterfaces() const { return false; }
-
-  void PauseIncomingMethodCallProcessing();
-  void ResumeIncomingMethodCallProcessing();
-
-  bool WaitForIncomingMethodCall(
-      MojoDeadline deadline = MOJO_DEADLINE_INDEFINITE);
-
-  void Close();
-  void CloseWithReason(uint32_t custom_reason, const std::string& description);
-
-  void set_connection_error_handler(const base::Closure& error_handler) {
-    DCHECK(is_bound());
-    router_->set_connection_error_handler(error_handler);
-  }
-
-  void set_connection_error_with_reason_handler(
-      const ConnectionErrorWithReasonCallback& error_handler) {
-    DCHECK(is_bound());
-    router_->set_connection_error_with_reason_handler(error_handler);
-  }
-
-  bool is_bound() const { return !!router_; }
-
-  MessagePipeHandle handle() const {
-    DCHECK(is_bound());
-    return router_->handle();
-  }
-
-  AssociatedGroup* associated_group() { return nullptr; }
-
-  void FlushForTesting();
-
-  void EnableTestingMode();
-
- protected:
-  void BindInternal(ScopedMessagePipeHandle handle,
-                    scoped_refptr<base::SingleThreadTaskRunner> runner,
-                    const char* interface_name,
-                    std::unique_ptr<MessageReceiver> request_validator,
-                    bool has_sync_methods,
-                    MessageReceiverWithResponderStatus* stub,
-                    uint32_t interface_version);
-
-  void DestroyRouter();
-
-  internal::Router* router_ = nullptr;
-};
-
-template <typename Interface, bool use_multiplex_router, typename ImplRefTraits>
-class BindingState;
-
-// Uses a single-threaded, dedicated router. If |Interface| doesn't have any
-// methods to pass associated interface pointers or requests, there won't be
-// multiple interfaces running on the underlying message pipe. In that case, we
-// can use this specialization to reduce cost.
-template <typename Interface, typename ImplRefTraits>
-class BindingState<Interface, false, ImplRefTraits>
-    : public SimpleBindingState {
- public:
-  using ImplPointerType = typename ImplRefTraits::PointerType;
-
-  explicit BindingState(ImplPointerType impl) {
-    stub_.set_sink(std::move(impl));
-  }
-
-  ~BindingState() { Close(); }
-
-  void Bind(ScopedMessagePipeHandle handle,
-            scoped_refptr<base::SingleThreadTaskRunner> runner) {
-    DCHECK(!router_);
-    SimpleBindingState::BindInternal(
-        std::move(handle), runner, Interface::Name_,
-        base::MakeUnique<typename Interface::RequestValidator_>(),
-        Interface::HasSyncMethods_, &stub_, Interface::Version_);
-  }
-
-  InterfaceRequest<Interface> Unbind() {
-    InterfaceRequest<Interface> request =
-        MakeRequest<Interface>(router_->PassMessagePipe());
-    DestroyRouter();
-    return std::move(request);
-  }
-
-  Interface* impl() { return ImplRefTraits::GetRawPointer(&stub_.sink()); }
-
- private:
-  typename Interface::template Stub_<ImplRefTraits> stub_;
-
-  DISALLOW_COPY_AND_ASSIGN(BindingState);
-};
-
-// Base class used for templated binding primitives which may bind a pipe to
-// multiple interfaces.
-class MOJO_CPP_BINDINGS_EXPORT MultiplexedBindingState {
- public:
-  MultiplexedBindingState();
-  ~MultiplexedBindingState();
+  BindingStateBase();
+  ~BindingStateBase();
 
   void AddFilter(std::unique_ptr<MessageReceiver> filter);
 
@@ -195,11 +91,8 @@ class MOJO_CPP_BINDINGS_EXPORT MultiplexedBindingState {
   std::unique_ptr<InterfaceEndpointClient> endpoint_client_;
 };
 
-// Uses a multiplexing router. If |Interface| has methods to pass associated
-// interface pointers or requests, this specialization should be used.
 template <typename Interface, typename ImplRefTraits>
-class BindingState<Interface, true, ImplRefTraits>
-    : public MultiplexedBindingState {
+class BindingState : public BindingStateBase {
  public:
   using ImplPointerType = typename ImplRefTraits::PointerType;
 
@@ -211,7 +104,7 @@ class BindingState<Interface, true, ImplRefTraits>
 
   void Bind(ScopedMessagePipeHandle handle,
             scoped_refptr<base::SingleThreadTaskRunner> runner) {
-    MultiplexedBindingState::BindInternal(
+    BindingStateBase::BindInternal(
         std::move(handle), runner, Interface::Name_,
         base::MakeUnique<typename Interface::RequestValidator_>(),
         Interface::PassesAssociatedKinds_, Interface::HasSyncMethods_, &stub_,